Duplicating method and element for use therein



United States Patent 3,076,406 DUPLICATING METHOD AND ELEMENT FOR USETHEREIN Robert T. Florence, Park Ridge, 111., assignor to A. B. DickCompany, Niles, Ill., a corporation of Illinois N0 Drawing. Filed Sept.28, 1954, Ser. No. 458,964 3 Claims. (Cl. 101-149.5)

This invention relates to a copy process and to materials for use in thepractice of same. It relates more particularly to a new and improvedprocess for the reproduction of multiple copies embodying improvementsover the present type of spirit or hectograph duplicating systems.

To the present, reproduction processes of the type described have beeneffected by systems generally referred to in the art as the gelatinsystem and as the spirit duplicating system. In the gelatin system, amaster sheet is imaged by typing, writing or drawing with an inkcomposition containing a water soluble dye, usually crystal violet. Theimage is transferred in reverse by absorption during contact into agelatin compound disposed in a pan or on the surface of a transfer sheetwhich then forms the printing medium. The water soluble dyestufftransfers from the moist printing medium to form copy upon contact withimpression medium.

In the spirit duplicating system, the' image is formed in reverse on amaster by transfer from a carbon type sheet coated with a compositioncontaining a high proportion of a water soluble dye such as crystalviolet, Victoria green, Victoria blue and the like. The image transfersfrom the master to copy sheets, the surfaces of which have been wettedwith an alcohol or alcohol and water combination upon contact, asbetween a compression cylinder and a printing plate mounted in a rotaryduplicating machine. The highly volatile solvents permit the productionof a larger number of copies and provide for more rapid drying of thecopy sheet to reduce setoff and smear. In the spirit duplicatingsystems, the dyestuif is preferably contained in a coating such as in acarbon sheet for trans fer in mirror image onto the printing master bythe application of force or the like.

While hectograph and presently known spirit duplicating systems of thetype described are desirable from the standpoint of their flexibility inuse and simplicity. in operation, these processes have for a number ofyears been confronted with serious objectionable features. The mostobjectionable characteristics stem from the .highly dispersible fineparticles of the dyestuff and from the highly soluble nature thereof inaqueous medium. The fine particle size of the dyestuif employed in thepractice of the present systems leads to objections in their use for themanufacture of carbon transfer sheets or inking ribbons employed in themanufacture of the imaged master. In most manufacturing processes, theatmosphere in and about the formulating and coating room becomescontaminated with fine particles of the dyestulf whereby the personnelwithin the buildings and the territory surrounding the buildings acquirea characteristic purplish color.

Because of the highly water soluble nature of the dyestulfs which havebeen employed to the present in the practice of the spirit hectographand duplicating systems, moisture on the hands of the operator issufficient to remove a suflicient quantity of the dyefrom which itgenerally spreads to other parts of the body and clothing. It isdifiicult even with the most extensive precautions to operate ahectograph or spirit duplicating system em bodying such dyestulfswithout staining ones hands and clothing and without finding suchdiscolorations from the dyestufr" existing on almost all surfaces withinthe vicinity of the duplicating machine. bjec of his provide a ystem3,076,406 Patented Feb. 5, 1963 2. which is as simple and as flexible asa spirit or hectograph duplicating system but which is substantiallyfree of such objectionable features of such prior art processes asheretofore employed.

Another object is to provide a duplicating system of the type describedwhich is free of compounds capable of coloring or dirtying ones hands,clothing, or the atmosphere or environment during the manufacture anduse of the elements employed in the copy process.

A further object is to provide a duplicating system in which permanentcopy of good quality is secured.

More specifically, it is an object of this invention to provide a newand improved duplicating system and materials for use in same whereinthe materials involved in the manufacture and use are incapable of colortransfer value and wherein the copy is developed in the copy sheetitself thereby to permit the formation of copy by reaction to produce aninsoluble product which remains permanently in the copy sheets.

In the copending application Ser. No. 287,616, filed May 13, 1952,description is made of an organic dye system which overcomes theobjectionable features of the present spirit and hectograph duplicatingsystems and which provides a new and clean duplicating processwithoutloss of the desirable features of the present processes. Asdescribed in the aforementioned application, instead of forming theimage on the master with a basic aniline dye that is highly soluble inwater or spirit solvents, as in the processes heretofore employed ingelatin or in spirit duplicating systems, the image is formed on themaster of a water and/or alcohol soluble component of an azo dye and inwhich the component has no objectionable color transfer value in thestate in which it exists in the master, imaging composition, inkingribbon or carbon sheet with which the master is formed but which upontransfer to the copy sheet forms an azo dyestuff by reaction with othercomponents contained in a non-reactive state in the imaged master orcontained in the fluid with which the copy sheet is wetted prior tocontact with the imaged master for effecting transfer of the imagingcomponents from the imaged master to the copy sheets or in the copysheet itself or else contained in a fluid applied to the copy sheetsubsequent to transfer of the imaging material from the master.

It has been found, in accordance with the practice of this invention,that similar concepts may be employed in a system which makes use of aWater and/ or alcohol soluble salt of a metal capable of reaction withanother preferably alcohol and/ or water soluble compound to form anintensely colored reaction product in the form of a complex of the twomaterials. As in the system of the aforementioned application, one ofthese compounds may be contained as the component free of any dye colorin the imaging master while the other is contained in the copy sheets orpreferably in the fluid with which the copy sheets are wetted prior tocontact with the imaged master or both of these components may becontained in the material with which the master is imaged when anothermaterial such as a base is employed as a component in the fluid or onthe copy sheets and which is used to control the reaction in forming theintensely colored complex as a reaction product.

The concepts of this invention may be capable of a number ofmodifications which will hereinafter be described in greater detail. Forpurposes of illustration, but not of limitation, examples will now begiven of one mode of carrying out the inventive concepts embodiedherein.

EXAMPLE 1 -Transfer sheet:

fibrous base sheet with a composition compounded of the followingmaterials:

12.0 percent by weight carnauba Wax 17.0 percent by weightmicrocrystalline wax 14.5 percent by weight heavy mineral oil 13.0percent by weight light mineral oil 1.5 percent by weight sodium oleate42.0 percent by weight nickel acetate The composition described above isreduced to a molten state at a temperature of about 80-90 C. forapplication as a hot melt onto the surface of the base sheet preferablyin concentrations ranging from 15-30 pounds per 3000 square feet ofsurface area. The applied coating remains as a layer concentrated on thesurface of the base sheet for enabling transfer onto an imaged masterbrought into surface contact therewith upon application of externalforce such as heat from a heat pattern or compression by means of atypewriter key, writing pencil, pen or stylus.

EXAMPLE 2 For preparation of the imaged master, the coated sheetmanufactured in accordance with Example 1 is positioned with the coatedside in surface contact with the prepared surface of a suitable mastersheet whereby coating material is displaced from the coated base sheetto the surface of the master to form a mirror image thereon in responseto forces applied against the uncoated side of the base sheet as by themeans described including die impression.

EXAMPLE 3 Fluid composition: Methanol containing dithiooxamide inconcentrations of 1 gram per liter of methanol.

EXAMPLE 4 Preparation of copy:

For the production of multiple copies, the imaged master prepared inaccordance with Example 2 is mounted on a cylinder of a rotaryduplicating machine of the conventional type used for spiritduplication. The copy sheets advanced through the machine are wetted asby means of a wick having an end portion immersed in a reservoir of thefluid of Example 3 prior to contact between the wetted surface of thecopy sheet and the imaged surface of the master. As the wetted surfaceof the copy sheet moves into surface contact with the imaged masterbetween the pressure roller and the cylinder mounting the master, someof the nickel acetate is leached from the imaging material for transferin small amounts to the copy sheets where reaction takes place betweenthe nickel acetate and the dithiooxamide to form a colored waterinsoluble reaction product.

In the preparation of a carbon sheet as described in Example 1, coatingsof the desired weight are preferably made from a hot melt applied onto asuitable paper base sheet by conventional coating technique, such as bya roller coater, knife coater, spray coater, dip squeeze proc- 'ess orthe like. The coating composition is incapable of flow when cooled toroom conditions but remains concentrated on the surface of the basesheet so as to be capable of transfer substantially completely incertain areas responsive to externally applied force to form a mirrorimage on the surface of a suitable master sheet placed in contacttherewith. While it is preferred to apply the coating composition as ahot melt in the manner described, the desired transfer coating may beformed on the base sheet by application of the materials from solventsolution, aqueous dispersion or emulsions. In the use of suchcompositions, the materials will usually be present in lesserconcentrations with the result that it will usually require more thanone coating to provide the desired coating weights on the base sheet.

It is desirable to embody as high concentration of the reactivecomponent as possible in the carbon coating consistent with the abilityof the coating to maintain the desired film characteristics and strengthfor transfer. Generally the amount of the reactive component present asan ingredient in the coating composition depends on the ability formaintain sufiicient fluidity under the conditions existing to achievethe desired application and coverage of the base sheet. For theproduction of a large number of copies of sufficient intensity, it isdesirable to maintain the concentration of the reactive component orcomponents in amounts greater than 20 percent by weight of the coatingand preferably in excess of 50 percent by Weight. In general, fluidityof the desired character falls off when the concentration of thereactive component or components for use in forming the image on thecopy sheet reaches 75 percent by weight of the composition but more maybe used with the introduction of suitable fluidizing agents. As themetal salt, it is preferred to make use of a water and/or alcoholsoluble salt of a metal having an intensely colored sulphide, such forexample as the water soluble salts preferably of nickel, cobalt, copper,lead and the like, and of iron, beryllium and the like. Instead ofnickel acetate in Example 1, use may be made of one or more of thefollowing metal salts in similar concentrations:

Nickel chloride Nickel formate Nickel sulphate Cobalt acetate Cobaltchloride Cobalt iodide Cobalt sulphate Copper acetate Copper lactateCopper nitrate Copper sulphate Lead acetate Lead formate Lead chlorideLead sulphate Ferric chloride Beryllium chloride Instead ofdithiooxamide, use may be made of other water and alcohol solublecompounds capable of reaction with the metals to form the desiredreaction products.

While it is more economical to place the water and alcohol soluble metalsalt in the carbon sheet or imaging material, it Will be evident thatthe concepts of this invention may be achieved when the dithiooxamide orequivalent material is compounded as a component in the carbon sheet orimaging composition with the soluble metal salt contained in the wettingout fluid or else in the copy sheet adapted to be wetted with a suitablefluid for leaching the reactive component from the imaging material ofthe master upon contact for reaction to form the copy as a coloredreaction product.

EXAMPLE 5 A coating composition for preparation of a transfer or carbonsheet embodying the modification described above may be formulated ofthe following:

8.5 percent by weight carnauba wax 14.0 percent by weight oxidizedmicrocrystalline wax 12.0 percent by weight petrolatum 15.5 percent byweight mineral oil 50.0 percent by weight dithiooxamide Application ofthe above onto a suitable paper base sheet may be made in weights ofabout 20 pound per 3000 square feet from a hot melt operating at atemperature of about -100 C.

When the imaging composition is formulated to contain the water oralcohol soluble dithiooxamide or other metal complexing compound asdescribed in Example 5, the

EXAMPLE 6 2.0 percent by weight nickel tormate 80.0 percent by weightmethanol 18.0 percent by weight water By way of still furthermodification, it is possible, in acordance with the practice of thisinvention, especially when the materials are dispersed as separateingredients in a non-solvent medium such as a wax base of the typedescribe-d in Examples 1 and 5, to place both the water and alcoholsoluble metal salt and the dithiooxamide or other water and alcoholsoluble thio or sulphur containing compound in the coating compositionor the imaging material. Under such circumstances, the fluid isformulated to contain the solvent for leaching the reaction productsfrom the imaged master and it may be formulated further to containalkali used to control the reaction and to produce more intense copy.

By way of still further modification, it is possible to embody one ofthe water or alcohol soluble components for the reaction in the imagingmaterial as illustrated in Examples 1 and 5 and then produce copy in theimpression paper by first wettingthe surfaces of the copy sheets with asolvent medium to leach some of the reactive component from the imagedmaster to the copy sheet and thensubsequently wet the surface of thecopy sheet witha second fluid system containing the other reactivecomponent such as dithiooxamide for use with the master imagedwith thecomposition of Example 1 or nickel acetate or the like metal salt foruse in producing copy with a master-imaged with the composition ofExample 5.

By way offurther illustration of the practice of this invention, thefollowing will set forth additional formulations for use of onecomponent in the coating and the other complexing compound in the fluid,but it will be understood that the various permutations previouslydescribed may similarly be employed by interchange of the reactivecomponents between the fluid and the imaging material or within aseriesof fluids as long as one of the components is present in the transfercoating or other material with which the master is imaged.

- EXAMPLE 7 Transfer coating:

23.4 percent by weightcarnauba wax 11.8 percent by weight castor oil11.8 percent by weight mineral oil 53.0 percent by weight iron chlorideEXAMPLE 8 Fluid for master imaged with composition of Example 7:-; v 1

33.0 percent by weight polyethylene glycol, molecular weight average6000 (Carbowax 6000) 34.0 percent by weight dimethyl glyoxime EXAMPLE 10Fluid for use with imaging material of Example 9:

90.0 percent by weight ammonium hydroxide (14% NH OH) 10.0 percent byweight nickel sulphate 6 EXAMPLE 11 Transfer coating:

EXAMPLE l2 Fluid for imaging composition of Example 11:

Saturated solution of ceric ammonium nitrate in l N hydrochloric acidEXAMPLE 13 Transfer coating:

33.0 percent by weight polyethylene glycol, molecular weight average6000 (Carbowax 6000) 33.0 percent by weight polyethylene glycol,molecular weight average 1500 (Carbowax 1500) 34.0 percent by weightalpha benzil dioxime EXAMPLE l4 Fluid for use with composition ofExample 13:

15 percent solution of copper sulphate in 28 percent solution ofammonium hydroxide EXAMPLE 15 Transfer coating:

33.0 percent by weight polyethylene glycol, molecular weight average6000 (Carbowax 6000) 33.0 percent by weight polyethylene glycol,molecular weight average 1500 (Carbowax 1500) 34.0 percent by weightphloroglucinol EXAMPLE l6 Fluid for master imaged with composition ofExample 15:

80.0 percent by weight water 20.0 percent by weight ferric nitrateEXAMPLE 17 Transfer coating:

33.0 percentby weight polyethylene glycol, molecularweight average 6000(Carbowax 6000) 33.0 percent by weight polyethylene glycol, molecularweight average 1500 (Carbowax 1500) 34.0 percent by weight Fe(NH )(SOEXAMPLE 18 I Fluid for master imaged with composition'o'f Ex ample 17:

Saturated alcoholic solution of 8-hydroxyquinoline EXAMPLE 19 Transfercoating:

30.0 percent by weight polyethylene glycol, molecular weight average6000 (Carbowax 6000) 60.0 percent by weight polyethylene. glycol,molecular weight average 1500 (Carbowax 15.00) 10.0 percent by weightberyllium chloride EXAMPLE 20 Fluid for transfer coating of Example 19:

Saturated alcoholic solution of quinalizarin EXAMPLE 21 Transfercoating:

11.0 percent by weight carnauba wax 15.0 percent by weight cardis wax15.0 percent by weight mineral oil heavy 13.0 percent by weight mineraloil light 1.5 percent by weight sodium oleate 55.5 percent by weightnickel acetate EXAMPLE 22 Fluid for use with master imaged withcomposition of Example 21:

12.0 percent by weight diethanolamine 3.0 percent by weight ethylcellosolve 10.0 percent by weight distilled water 74.0 percent by weightmethanol 1.0 percent by weight potassium dithiooxalate Instead ofpotassium dithiooxalate which gives red copy, use may be made ofcorresponding amounts of thiosalicylic acid (brownish violet),p-dimethylaminobenzylidene (brownish red) or dithiooxamide (bluishblack) copy.

The transfer coatings may be applied by hot melt or solutions or fromdispersions as previously described.

It will be further understood that the concepts of this invention arenot limited to the use of the reactive component in a transfer coatingemployed in the manufacture of an imaged master but that the conceptsmay be practiced by the use of imaging materials of the type describedin the form of typewriter ribbons, writing inks, drawing crayons or thelike embodying one or more of the substantially colorless reactivecomponents of the type described in preparation of the imaged masterwith the other component for completing the reaction to form the coloredreaction product in the fluid or in the copy sheet for reaction todevelop the copy as an incidence to the transfer of the one componentfrom the imaged master to the copy sheet. The compositions of suchinking materails or crayons or typewriter ribbons may be formulated witha conventional base containing the reactive component in relatively highconcentrations.

It will be apparent from this description that a completely new andimproved duplicating process is provided herein capable of use inconventional hectograph duplicating machines or in conventional spiritduplicating machines to produce copy of improved quality without fear ofset-off and without fear of dirtiness caused by discoloration by thevarious materials involved. Until the reaction product is formed in thecopy sheets, the elements involved in the preparation of the master, inthe manufacture of the imaging compositions and in the elements presentin the materials used to produce the imaged master or in the imagedmaster itself remain wholly free of any color transfer value andtherefore avoids dirtiness which is the most objectionable feature ofprocesses which have heretofore been employed. It will be evident thatthe imaging material in the transfer sheet, master sheet or in otherimaging compositions is free of any color and may be handled in a normalmanner without staining or dirtying ones hands or clothing and equipmentand the imaged master may be filed away for subsequent use to obtainadditional copies without loss of definition or quality of the copyproduced.

It will be understood that changes may be made in the details of thecompositions, their formulations and their arrangement and method of usewithout departing from the spirit of the invention, especially asdefined in the following claims.

I claim:

1. A transfer sheet for use in the preparation of an imaged duplicatingmaster from which multiple copies can be produced comprising a basesheet and a composition, the major proportion of which exists as acontinuous transfer coating concentrated on the surface of the basesheet to permit substantially complete displacement therefrom inselected areas, said composition containing a high concentration ofnickel acetate and dithiooxamide and a wax carrier in which thedithiooxamide and nickel acetate are insoluble and in which the nickelacetate and dithiooxamide are present as dispersed phases in the waxmatrix dispersed as separate ingredients in the coating.

2. The method of producing multiple copies by a duplicating processusing a master imaged with a material containing a large proportion of awater and alcohol soluble salt of a polyvalent metal capable of reactionwith a sulfide ion to form a highly colored polyvalent metal sulfide anda water and alcohol soluble organic thio compound capable of releasingsulfide ions from solution in a medium selected from the groupconsisting of alcohol and water and wherein the materials are dispersedas separate components in a wax matrix in which both of the compoundsare insoluble, comprising contacting the imaged surface of the masterwith copy sheets wetted with a fluid which is a solvent for the sulphurcontaining compound and the metal salt whereby some of each of thecompounds is leached for transfer from the imaged master to the copysheets while in solution whereby reaction can take place to form thecolored reaction product in the copy sheets.

3. The method of producing by a duplicating process using a masterimaged with a material containing a large proportion of dithiooxamideand nickel acetate, dispersed as separate components in a wax carrier inwhich both of the materials are insoluble, comprising contacting theimaged surface of the master with copy sheets previously wetted with afluid which is a solvent for the dithiooxamide and nickel acetate andwhich contains alkali in solution whereby some of the dithiooxamide andnickel acetate is leached for transfer from the imaged master to thecopy sheets where reaction takes place to form the colored reactionproduct.

References Cited in the file of this patent UNITED STATES PATENTS823,691 Ligon June 19, 1906 1,050,236 Schmitt Jan. 14, 1913 1,917,370Hickmann July 11, 1933 2,038,486 Glas Apr. 21, 1936 2,073,033 Szasz Mar.9, 1937 2,146,976 Neidich Feb. 14, 1939 2,168,098 Groak Aug. 1, 19392,217,349 Neidich Oct. 8, 1940 2,316,340 Kohn Apr. 13, 1943 2,663,656Miller et al. Dec. 22, 1953 2,748,024 Klimkowski et al. May 29, 19562,755,200 Balon et al. July 17, 1956 2,936,707 Maguire et al. May 17,1960

2. THE METHOD OF PRODUCING MULTIPLE COPIES BY A DUPLICATING PROCESSUSING A MASTER IMAGED WITH A MATERIAL CONTAINING A LARGE PROPORTION OF AWATER AND ALCOHOL SOLUBLE SALT OF A POLYVALENT METAL CAPABLE OF REACTIONWITH A SULFIDE ION TO FORM A HIGHLY COLORED POLYVALENT METAL SULFIDE ANDA WATER AND ALCOHOL SOLUBLE ORGANIC THIO COMPOUND CAPABLE OF RELEASINGSULFIDE IONS FROM SOLUTION IN A MEDIUM SELECTED FROM THE GROUPCONSISTING OF ALCOHOL AND WATER AND WHEREIN THE MATERIALS ARE DISPERSEDAS SEPARATE COMPONENTS IN A WAX MATRIX IN WHICH BOTH OF THE COMPOUNDSARE INSOLUBLE, COMPRISING CONTACTING THE IMAGED SURFACE OF THE MASTERWITH COPY SHEETS WETTED WITH A FLUID WHICH IS A SOLVENT FOR THE SULPHURCONTAINING COMPOUND AND THE METAL SALT WHEREBY SOME OF EACH OF THECOMPOUNDS IS LEACHED FOR TRANSFER FROM THE IMAGED MASTER TO THE COPYSHEETS WHILE IN SOLUTION WHEREBY REACTION CAN TAKE PLACE TO FORM THECOLORED REACTION PRODUCT IN THE COPY SHEETS.